UWB technologies have attracted attention as communication technologies in recent years. Although these technologies use extremely broad frequency bands, they are extremely low in power spectral density and therefore have the advantage of being able to share frequencies already in use. Moreover, they have advantages such as that by using short pulses of several hundred picoseconds or shorter, they make it possible to perform high-resolution position detection and the like.
In conventional microwave/milliwave band UWB technology, a high-frequency pulse signal generating device is configured with the high-frequency pulse signal generator and an ultra-wideband antenna connected by a transmission line (see, for example, Non-patent Document 1, Non-patent Document 2, and Patent Document 1).
[Non-patent Document 1] Yun Hwa choi, “Gated UWB Pulse Signal. Generation,” Joint with Conference on Ultra wideband. Systems and Technologies Joint UWBST & IWUWBS. 2004 International Workshop on, pp. 122-124.
[Non-patent Document 2] Ian Gresham, “Ultra-Wideband Radar Sensors for Short-Range Vehicular Applications”, MTT VOL. 52, No. 9, pp. 2111-2113, September 2004
[Patent Document 1] Published Japanese Translation 2003-515974 of PCT Application
The high-frequency pulse signal generators described in Non-patent Document 1, Non-patent Document 2 and Patent Document 1 are configured by the method of using an ultra-wideband filter circuit to pass only a certain part of the frequency components of a base band signal (monopulse signal or step signal generated in accordance with the base band signal), by the method of modulating the output of a CW signal oscillator such as by passing/blocking it in a high-speed RF switch, or by a combination thereof.
On the other hand, there has also been proposed a high-frequency pulse signal generating device in which the transmission line or resonant circuit is replaced by an antenna. (see, for example, Patent Document 2 and Patent Document 3).
[Patent Document 2] Unexamined Japanese Patent Publication 2004-186726
[Patent Document 3] Unexamined Japanese Patent Publication 2007-124628
The high-frequency pulse signal generating devices described in Patent Document 2 and Patent Document 3 are of the type that load a charge in an antenna that is the transmission line or resonant circuit and rapidly discharging the charge using a high-speed switch or the like. Among the frequency components generated by the high-speed discharge, the frequency components of the resonant frequency band of the antenna constituting the resonant circuit are radiated.